Hieam clark



(No Model.)

H. CLARK.

GOUNTBRSINK.

N0. 358,731. PatentedlVIar. 1,1887.

irren.

HIRAM CLARK, QF SYRACUSE, NEV YORK.

COUNTERSINK.

SPECIFICATION` forming part of Letters Patent No. 358,731, dated March 1, 1887 Application filed December 6,1886. Serial No. 220,819. (No model.)

.To all whom it may concern.-

Be it known that I, HIRAM CLARK, of Syracuse, county of Onondaga, in the State of N ew York, a citizen of the United States, have invented certain new and useful Improvements in Countersinks, dac., of which the following is a specification, reference being had to the accompanying drawings, in Which- Figure 1 is an edge elevation of a countersink; Fig. 2, a face elevation of same, and Fig. 3 an elevation showing the parts unsecured and swung apart upon the pivot.

Similar letters and figures of reference indicate corresponding parts throughout the several views.

My invention cornprehends dividing the head and shank of a oountersink into two or more longitudinal segmental parts, or I can so divide the head and a portion of the shank, such segments being pivoted or otherwise secured together.

My invention relates to countersinks, burrs, cherries, centers, and all that kind of tools used either in wood or metal. It is constructed as follows:

A is the shank, shown in the drawings as divided longitudinally into segments l 2.

The back end may be round or squared off for insertion into a bit-stock or chuck. In fact, the shank may be of any forni desired.

Upon the outer end of the shank I form a shoulder, 3, also bisected, and through the segments of this shouldered portion I drill and thread the coincident screw-holes4 5, or Ican widen out the hole 4 into a slot transverse to that shoulder-segment and only thread the hole 5, so that the shank-segments can be adjusted.

B is the head, bisected on the same line as the shank, as shown in the drawings, both segments being integral with the shank-segments respectively. The front end of the head is beveled, as shown, forming tapering eutting-edges, which edges may be straight or curved, or of any desired form.

The cutting-edge portions are connected to the shank-segments by necks 6 7, the interior of the head being hollowed out to forni a chipcavity, 11, within it, which cavity opens out through the rear `part of the head, or both sides thereof, through the throat 8, between the necks, Yfor the escape of the chips.

The shank-segments are pivoted together by a pivotal rivet, 9, which rivet can be located at any point desired in the shank.

I construct my sectional or segmental tool in such manner that when the cutting-edges become dull by removing the screw l0 I can swing the segments around, so as to sharpen the cutting-edges upon astone, using the stone upon the inside, and not disturbing the outer faces of the head-segments.

When constructed of more than two segmental parts, in place of the screw 10 I can use any ordinary kind of spring clamping-collar to hold the parts in position.

'Ihe dotted lines in Figs. 2 and 3 (marked X) show one form of construction where the whole head and a portion only of the shank are bisected longitudinally, in which ease by removing the screw .l0 the segments come apart for sharpening. When the hole 4 is enlarged or made into a slot, the segments can be adjusted to increase or diminish the cnt of the cutting-edges.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. A countcrsink consisting of a shank and head, the latter divided into two longitudinal segmental parts, the edge or edges of each bcing a cutting-edge, substantially as described, and for the purposes set forth.

2. A countcrsink Consisting of two segmental shank portions and two segmental head portions pivotally connected together, substantiall y as described,and for the purposes set forth.

3. A countersink consisting of two segmental shank portions and two segmental head portions connected together by a pivotal rivet, and secured in position by aserew passing through the shank-segments adjacent to the head, substantially as described, and for the purposes set forth.

In witness whereof I have hereunto set my hand this 3d day of December, 1886.

HIRAM CLARK. In presence of- WM. C. RAYMOND, A. D. ALLEN. 

